An image pickup device which is called a camera module has come to be mounted on a mobile terminal representing a compact and thin-type electronic hardware such as a cellular phone and PDA (Personal Digital Assistant), whereby, it has become possible to transmit mutually not only voice information but also image information to a remote location. As image pickup elements used for these image pickup devices, a solid-state imaging device such as a CCD type image sensor and a CMOS type image sensor are used. In recent years, increase of pixel numbers of the image pickup element have been advanced, and enhancement of its resolution and performance have been attained.
As a lens for image pickup which forms an image of a photographic object on the imaging pickup element, a lens made of resin, which is suitable for mass production with low cost has come to be used for cost reduction. In addition, the lens made of resin is excellent in terms of its workability and has satisfied requirements for enhancement of its performance, by being formed in an aspheric shape. With regard to an image pickup lens of this kind used for an image pickup device housed in a mobile terminal, a demand for the compatibility between further compactness and mass productivity required for the mobile terminals are strong and it is becoming difficult to meet the requirement by image pickup lenses structured by using only resin materials.
To solve these problems, there has been proposed a method to produce a large number of lenses for image pickup as follows. Plural lens parts made of curable resin are formed on a wafer shaped glass substrate in a size of several inches through a replica method (resin is formed into plural pieces in the lens shape on the glass substrate), and then the glass substrate is cut off into each separate lens part. Lenses manufactured by this method are called wafer lenses, and arts regarding pickup lenses of these types are disclosed in Patent Literatures 1 to 3.